Adhesive film composition

ABSTRACT

A thermoplastic film, adapted for adhesion, composed of a compound of polyamide-based thermoplastic elastomers and of copolymers of olefins, the latter preferably being constituted of at least two different monomers of olefins. The composition of the thermoplastic film is such that the thermoplastic elastomers represent at least 50% and preferably 60% of the total weight of the compound.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationsSer. No. 07/708,016, now abandoned, and Ser. No. 07/708,017, pending,both filed Jun. 3, 1991, in the names of Thierry VASSELIN, MichelVUACHET, Gilles RECHER, and Myriam SERVES, claiming priority of FrenchApplication No. 90 07,044 filed Jun. 1, 1990, and French Application No.90 06,869 filed on Jun. 1, 1990, the disclosures of which are herebyincorporated in their entireties by reference thereto herein.

This application is also a division of application Ser. No. 07/714,183,filed on Jun. 14, 1991, now U.S. Pat. No. 5,348,804.

This application also claims the priority of French Application No. 9007,600 filed Jun. 14, 1990 and French Application No. 90 07,420 filedJun. 14, 1990, the disclosures of which we hereby incorporated in theirentireties by reference thereto herein.

FIELD OF THE INVENTION

The present invention relates to thermoplastic materials used as filmsadapted for adhesion which are composed of a thermoplastic elastomer(TPE) comprising a polyamide and of copolymers of modified olefins, aswell as processes for adhesion of elements of an article of manufacture,such as a ski structure, using such thermoplastic materials and films.

DISCUSSION OF BACKGROUND AND MATERIAL INFORMATION

In the field of the plastic films, "hot melt" films are well known.French Patent No. FR 2,523,143 describes an adhesive whose compositioncontains at least about 35% by weight ethylene based copolymers, atleast one vinylic ester, and from 0.5 to 20% of a copolyetheresteramide.

European Patent Application No. 312,968 describes the use of adhesivefilms of the "hot melt" type for the assembly of elements of a skistructure. These films are basically composed of a thermoplastic polymerand of an adhesion promoting agent, such as a silane or an epoxy resin.

SUMMARY OF THE PRESENT INVENTION

An object of the present invention is a film comprising a newcomposition, adapted for adhesion, which possesses improved adhesionproperties, and may be applied to a variety of materials and elements,preferably in the production of an article of manufacture, such as aski.

Another object of the invention is to improve the thermal retention ofthe adhesion of elements of a structure, such as a ski, that is formedusing the adhesive film of the thermoplastic materials of the presentinvention.

An advantage of the films of thermoplastic materials of the presentinvention is that they are more economical to manufacture and implementwhen compared to currently known films.

The present invention relates to films or sheets of thermoplasticmaterial, adapted for adhesion, having a composition comprising at leastone thermoplastic elastomer (TPE) based on polyamides and a copolymer ofmodified olefins.

The present invention is directed to a process for assembling elementsof a ski structure which involves adhering a first element having ajunction surface to at least a second element having a Junction surfaceby placing at least one adhesive layer between junction surfaces of thefirst element and the second element, and placing at least onethermoplastic film having a composition comprising a polyamide basedthermoplastic elastomer and a copolymer of modified olefins between saidadhesive layer and the junction surface of said first element to resultin a ski structure.

The present invention is also directed to a ski structure which iscomposed of at least a first element having a junction surface; athermoplastic film laving a composition comprising a polyamide basedthermoplastic elastomer and a copolymer of modified olefins placed onthe junction surface; an adhesive layer applied to the thermoplasticfilm; and at least a second element having a Junction surface adhered tothe adhesive layer.

For purposes of the processes and resultant structures, such as skis, ofthe present invention the copolymer of modified olefins preferablyincludes either at least one member selected from the group consistingof olefin monomers, or at least one comonomer selected from the groupconsisting of vinylic esters of saturated carboxylic acids, saturatedmono-carboxylic acids, saturated di-carboxylic acids, esters ofsaturated mono-carboxylic acids, esters of saturated di-carboxylicacids, salts of saturated mono-carboxylic acids, salts of saturateddi-carboxylic acids, anhydrides of saturated di-carboxylic acids, andanhydrides of unsaturated di-carboxylic acid. Preferably, the copolymerof modified olefins is an ethylene-propylene grafted copolymer.

In accordance with the present invention, the thermoplastic elastomerincludes at least about 50% by weight of the composition, and preferablyat least about 60% by weight of said composition. For the purposes ofthe present invention the ethylene propylene grafted copolymer may begrafted by a member selected from the group consisting of carboxylicacid, an anhydride of carboxylic acid, and a salt of carboxylic acid.Preferably, the copolymer includes at least two monomers of differentolefins, and more preferably the copolymer is selected from the groupconsisting of maleic ethylene and propylene dienes, and maleic ethyleneand propylene rubbers, such as a maleic ethylene and propylene diene, ora maleic ethylene and propylene rubber, wherein the maleic ethylene andpropylene rubber comprises between about 0.1% to about 2% by weightmaleic anhydride.

For the purpose of the present invention, the copolymer of modifiedolefins may include at least one modified copolyolefin selected from thegroup consisting of statistical copolymers and sequenced copolymers,wherein the copolyolefins comprise at least one member selected from thegroup consisting of i) at least two monomers of different olefins, andii) at least one comonomer selected from the group consisting of vinylicesters of saturated carboxylic acid, saturated mono-carboxylic acids,saturated di-carboxylic acids, esters of saturated mono-carboxylicacids, esters of saturated di-carboxylic acids, salts of saturatedmono-carboxylic acids, salts of saturated di-carboxylic acids,anhydrides of saturated di-carboxylic acids, and anhydrides ofunsaturated di-carboxylic acids, wherein said olefins represent at least50% of the total weight of said copolymer, and preferably comprise atleast 60% by total weight of said copolymer, and

wherein the weighted ratio of ##EQU1## is greater than about 50%, andpreferably is greater than about 60%.

In accordance with the present invention, the polyamide basedthermoplastic elastomer includes a copolymer selected from the groupconsisting of statistical copolymers and sequenced copolymers, whereinthe sequenced copolymers comprise polyetheresteramides, and thepolyetheresteramides comprise sequenced polyamides having an averagemolecular weight of between about 500 and about 10,000, and preferablybetween about 600 and about 5,000, and wherein the polyetheresteramidescomprise polyethers which have an average molecular weight of betweenabout 200 and about 6,000, and preferably between about 600 and about3,000.

For purposes of the present invention, the adhesive layer may include amaterial selected from the group consisting of resin and a foam, whereinthe thermoplastic film is interspersed between the adhesive layer andthe junction surface. Preferably, the adhesive layer includes a memberselected from the group consisting of epoxy adhesives, polyesteradhesives, and polyurethane adhesives, wherein the adhesive layer andthe second element comprise a preimpregnated, partially cross-linkedassembly. The junction surface of the first element may include at leastone member selected from the group consisting of polyamides,polyethylenes, polyethylene terephthalates, polybutadieneterephthalates, polypropylenes, aluminum, processed aluminum, steel, andmetal alloys, and preferably a polyamide film. The first element ispreferably an exterior element of a ski.

A process of the present invention also involves subjecting the skistructure to heat to cross-link the thermosettable adhesive.

For purposes of the present invention, the polyamide-based thermoplasticelastomer comprises a polyetheramide, preferably, wherein thepolyetheramide comprises a polyetheresteramide. The modifiedcopolyolefin may be selected from the group consisting of maleicethylene and propylene rubbers, and maleic ethylene, propylene and dienecopolymers.

For the purposes of the present invention the thermoplastic film mayinclude at least one member selected from the group consisting offillers, pigments, dyes, and additives, preferably wherein the fillersare present in amounts up to about 50% by weight and more preferably upto about 40% by weight of the polyamide-based thermoplastic elastomerand copolyolefin. The adhesive may be a thermosettable adhesive which isselected from the group consisting of epoxy resins, polyester resins,and polyurethane resins.

In accordance with the present invention, the thermosettable adhesiveand the second element may comprise a pre-impregnated, partiallycross-linked assembly. Also, the Junction surface of the first elementmay include at least one material selected from the group consisting ofpolyamide, polyethylene, polyethylene terephthalate, polybutadieneterephthalate, polypropylene, aluminum, processed aluminum, aluminumalloys, steel, and metal alloys, and preferably wherein the firstelement is a polyamide film. The first element may be a decorativeelement or a protective element for a ski.

A process of the present invention also involves placing the firstelement, the polyamide-based thermoplastic film and the second elementin a mold, injecting an expandable polyurethane foam into the mold andpermitting the polyurethane foam to harden and adhere to thepolyamide-based thermoplastic film and the first element.

A process of the present invention also involves coextruding the firstelement and the polyamide film in a single step.

The present invention is also directed to a film adapted for adhesion,which includes at least one polyamide based thermoplastic elastomer; andat least one modified copolyolefin selected from the group consisting ofstatistical copolymers and sequenced copolymers, said copolyolefinscomprising at least one member selected from the group consisting of i)at least two monomers of different olefins, and ii) at least onecomonomer selected from the group consisting of vinylic esters ofsaturated carboxylic acid, saturated mono-carboxylic acids, saturateddi-carboxylic acids, esters of saturated mono-carboxylic acids, estersof saturated di-carboxylic acids, salts of saturated mono-carboxylicacids, salts of saturated di-carboxylic acids, anhydrides of saturateddi-carboxylic acids, and anhydrides of un saturated di-carboxylic acids,wherein said olefins represent at least 50% of the total weight of saidcopolymer, and preferably at least 60% by total weight of saidcopolymer, preferably wherein the weighted ratio of ##EQU2## is greaterthan about 50%, i.e., greater than about 60%.

A process of the present invention also involves assembling elements ofa composite material by adhering at least one first element having ajunction surface and a second element having a junction surface byplacing an adhesive layer of a material selected from the groupconsisting of a resin and a foam between Junction surfaces of the firstelement and the second element, interspersing a thermoplastic filmhaving a composition comprising polyamide based thermoplastic elastomerand a copolymer of modified olefins between the adhesive layer and thejunction surfaces, preferably wherein the adhesive layer comprises epoxyadhesives, polyester adhesives, and polyurethane adhesives, and theadhesive layer and the second element comprise a pre-impregnatedpartially cross-linked assembly. The junction surface of said firstelement may comprise at least one member selected from the groupconsisting of polyamides, polyethylenes, polyethylene terephthalates,polybutadiene terephthalates, polypropylenes, aluminum, processedaluminum, aluminum alloy, steel, and metal alloys, and is preferably apolyamide film. The first element preferably comprises an upper elementfor decoration and protection of a wind surfer.

In accordance with the present invention, the first element and thepolyamide film may be coextruded in a single step.

The process of the present invention may involve placing the firstelement, the thermoplastic film, and the second element in a mold, andinjecting an expandable polyurethane foam into said mold and permittingthe foam to expand, harden and adhere to the adhesive film and to thefirst element.

A process of the present invention also involves forming a thermoplasticfilm having a composition comprising a polyamide-based thermoplasticelastomer and a copolymer of modified olefins into a packaging material,such as sheaths and bags.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, characteristics and advantages will become apparent fromthe description and the embodiments that follow, along with the annexedfigures in which:

FIGS. 1-4 illustrate a process of assembly by adhesion according to afirst embodiment of the invention;

FIGS. 5 and 6 illustrate a process of assembly by adhesion according toanother embodiment;

FIGS. 7 and 8 illustrate a process of assembly by adhesion according toother embodiments.

DETAILED DESCRIPTION

The present invention relates to a film having a composition comprisingof polyamide based thermoplastic elastomers and copolymers of modifiedolefins.

Preferably, the composition of the present invention comprises at least50% and preferably at least 60% thermoplastic elastomer based on of thetotal weight of the composition.

The polyamide based thermoplastic elastomer component of the compositionof the present invention may be statistical or sequenced copolymers.

The copolymers of the polyamide based thermoplastic elastomer of thecomposition of the present invention are formed by a random chainformation of the different components, e.g., monomers and/orprepolymers, while the sequence or block copolymers, which arepreferred, are formed from blocks having a certain chain length of theirdiverse components.

These polyamide based copolymers are preferably selected from the groupconsisting of polyester amides and polyether amides.

The sequenced polyether amides or the block polyether amides essentiallyresult from the copolycondensation of reactive end polyamide sequenceswith reactive end polyether sequences, representative examples of whichare selected from the group consisting of:

a) polyamide sequences at the end of diamine chains with polyoxyalkylenesequences at the end of di-carboxylic chains;

b) polyamide sequences at the end of di-carboxylic chains withpolyoxyalkylene sequences at the end of diamine chains obtained bycyanoethalation and hydrogenation of alpha, omega, dihydroxylicaliphatic polyoxyalkylene sequences referred to as polyetherdiols; and

c) polyamide sequences at the end of di-carboxylic chains withpolyetherdiols, referred to as polyetheresteramides, which areespecially preferred.

The composition and the manufacture of such polyetheramides have beendescribed in the French Patents 2,273,021 and 2,401,947 whose contentscomplement the present description, and their counterpart U.S. Pat. Nos.4,230,838, and 4,332,920; and U.S. Pat. No. 4,252,920, respectively, thedisclosures of which are hereby incorporated in their entireties byreference thereto herein.

The average molecular weight or mass in number of these polyamidesequences is generally between 500 and 10,000 and preferably between 600and 5000.

The polyamide sequences of polyetheresteramides are formed preferably byat least one member selected from the group consisting of aliphaticpolyamides, amorphous polyamides, mixtures of aliphatic polyamides andamorphous polyamides, and of copolyamides resulting from thepolycondensation of their monomers.

The average molecular mass in number of polyethers is generally between200 and 6,000, and more precisely between 600 and 3,000.

The polyether sequences preferred are selected from the group consistingof polytetramethylene glycol (PTMG), polyethylene glycol (PEG) andpolypropylene glycol (PPG).

The inherent viscosity of polyetheresteramides is advantageously betweenabout 0.8 and 2.05. The viscosity of polyetheresteramide is measured inmetacresol at 22° C. with an initial concentration of 0.5 g of polymerfor 100 g of metacresol.

The polyetheresteramides may be formed of from about 5 to about 85% byweight of polyether, from about 95% to about 5% by weight of polyamide,and preferably from about 30% to 85% by weight of polyether and fromabout 70% to about 15% by weight of polyamide.

The polyetheresteramides preferred are those whose polyamide sequencesare selected from the group consisting of PA-11, 12 and/or 12.12.

When a composition with anti-static properties is desired, onepreferably uses the polyetheresteramides whose polyether sequences areselected from the group consisting of polyethylene glycol (PEG).

The second component of the composition of the present invention is acopolymer of modified olefins.

The copolymers of modified olefins, also referred to herein as modifiedcopolyolefins, include copolymers selected from the groups consistingof:

a) at least two monomers of different olefins; and

b) at least one comonomer selected from among vinylic esters ofsaturated carboxylic acid, unsaturated mono- and di- carboxylic acids,esters of mono- and di-carboxylic acids, salts, saturated or unsaturateddi-carboxylic acid anhydrides.

Preferably the copolymer of modified olefins comprises at least twodifferent clef in monomers.

The olefins may represent at least about 50%, and preferably at leastabout 60%, of the total weight of the copolymer, it being understoodthat the copolymers of modified olefins used in accordance with thepresent invention may be polymerized in a statistical or sequencedmanner, and may have a linear, or branched, structure.

The preferred copolymers include the copolymers selected from the groupconsisting of ethylene and of propylene grafted by a carboxylic acid, ananhydride of a carboxylic acid, and an acid salt, preferably of acarboxylic acid.

Among the acids, the preferred choices include members selected from thegroup consisting of unsaturated di-carboxylic acid, such as maleic acid,and fumaric acid.

The anhydrides and salts that are chosen are those that correspond tothe above-identified acids.

Representative examples of copolymers of modified olefins includemembers selected from the group consisting of maleic ethylene propylenedienes (EPDM).

The copolymers of modified olefins may be polymerized in a statisticalor sequenced fashion, and have either a linear or a branched structure,examples of which include members selected from the group consisting of:

maleic ethylene and propylene rubbers (EPRm), preferably between aboutcontaining 0.1 to 2% by weight of maleic anhydride; and

maleic ethylene, propylene and diene copolymers (EPDMm).

The films or sheets particularly preferred for purposes of the presentinvention are composed of a composition comprising at least about 50% byweight, and preferably at least about 60% by weight, polyetheresteramideand of a propylene-ethylene copolymer containing about 0.1% to about 2%by weight of grafted maleic anhydride.

To the composition of the present invention described above, which isparticularly useful when formed into a film, diverse other componentscan be incorporated, such as fillers, pigments, dyes, and otheradditives.

Examples of fillers include members selected from the group consistingof fiberglass, carbon, aramide, talc, silicon, china clay, glass fibersand beads, ceramics, metallic charges, salts and metallic oxides, suchas aluminum powder, calcium and manganese carbonates, ferrite powder andtitanium oxide. Generally, one can incorporate up to about 50% andpreferably up to about 40% by weight of fillers with respect to thecomposition comprising thermoplastic elastomer and copolymers ofmodified olefin in accordance with the present invention.

Examples of additives include members selected from the group consistingof anti UV agents, demolding agents, and shock modifying agents.

In view of their simple implementation, their good mechanical properties(especially resistance to cold shocks, abrasion and resistance to tear),their dimensional stability between -20° C. and 60° C., their positiveaging, as well as of their excellent aptitude for adhesion anddecoration, the films composed of the composition of the presentinvention may be used alone or for the manufacture of complex orcomposite objects, such as duplicate molding of elements, coextrudedfilms, laminates, and other structures of assembled elements, such asski structure.

The films and sheets of thermoplastic elastomer composition of thepresent invention are obtained by any known process of extrusion, suchas extrusion-flat calendaring, extrusion-coating with acrylic resin, orextrusion-blowing. In such cases, the extrusion temperature is generallybetween 190° C. and 250° C.

According to the Modern Plastic Encyclopedia, the term "film" isreserved for objects with planar section whose thickness is less than250 μm, and the term "sheet" is reserved for objects with a greaterthickness, and which can attain several millimeters. In all thatfollows, and for reasons of simplification, the terms can be used assubstitutes for one another and simultaneously designate both films andsheets. The films according to the invention may be used "as is" but mayalso be used for the manufacture of multi-layer films, obtained forexample, by coextruston, and by heat lamination.

Single layer films are particularly adapted for adhesion on fabrics andnon-woven materials, and for covering natural or synthetic fibers withfoam.

The multi-layer film especially preferred comprises a layer of materialselected from the group consisting of aliphatic polyamide, examples ofwhich are selected from the group consisting of PA-6, PA-6.6, PA-11,PA-12, PA-12.12, of amorphous polyamide, of polyamide basedthermoplastic elastomer, and of copolymers of ethylene and vinylicalcohol (EVOH); and a film according to the present invention.

The films of the present invention may be adhered Onto rigid elements,and especially on metallic elements, such as cables and sheet metal, aswell as on synthetic materials, examples of which are preferablyselected from the group consisting of materials based on epoxy resin,polyesters and polyurethanes, or elements coated or impregnated with thepreceding materials, i.e., an epoxy resin base, and/or polyesters and/orpolyurethanes.

The process of manufacture of these composite materials is generallyperformed in two steps:

In the first step, the multilayer film is coextruded, and then in thesecond step, the multilayer film is heat glued from the side of thelayer of the composition according to the invention onto the supportmade, for example, of synthetic material, for example, by heat formingor thermal forming.

These composite materials may be decorated using the method oftransferring impressions of subliminal ink, and preferably using theprocesses described in the patent application FR 2,596,286. The decor ofthese materials may also be done according to other techniques, such asserigraphy, painting or polishing, heat transfer, tampography, ink jet,and laser marking.

The composite materials comprising the dual layer film described aboveand a support impregnated with at least one member selected from thegroup consisting of an epoxy resin, polyester, and polyurethane, whichmay ultimately be decorated, are particularly preferred for themanufacture of skis, particularly the upper cosmetic layer of skis, ofwind surfers, of skate boards, of surf boards, of boat hulls, anddecoration panels for lower body parts of automobiles, anti-noiselaminates, and thermal insulations.

Single layer films can also be used as bonds for coextrusion ofmultilayer films, particularly multilayer films whose adhesion isdifficult, thus enabling those layers to be glued together.

As examples, film compositions according to the present invention may beused as coextrusion bonds for a polycarbonate (PC) based film and for anethylene and vinylic alcohol (EVOH) based films.

These single or multilayer films of the present invention areparticularly adapted to the manufacture of complex foams and fabricsaccording to the technique known as "foam baking".

In a laminating machine, at least one assembly composed of a piece offabric, of a film according to the present invention, and possibly of alayer of foam, is superposed one on top of the other, and then thecomplex described above is heat laminated.

After cooling, the complex is positioned in a mold and injected withthermosettable or thermohardenable foam, for example, of thepolyurethane type. The in situ expansion reaction of the components ofthe foam brings about the adhesion of the complex on the foam.

The presence of the film of the present invention between the piece offabric and the foam is particularly advantageous because it stops thepenetration of the foam through the fabric. Such composites areespecially adapted for the manufacture of seats, especially car seats,as well as for isothermic combinations.

The present invention also relates to processes of adhesion of a filmaccording to the invention for the manufacture of a composite materialmanufactured by the assembly of several elements coated or impregnatedwith a thermosettable adhesive of the epoxy and/or polyester type, or,for example, of a polyurethane foam. Although this adhesive must becompatible with all the elements to be assembled, these bonds do notgenerally suffice for the adhesion of all the elements that one may wishto use for this purpose. In order to obtain the adhesion of certainelements, therefore, it is proposed to use the thermoplastic adhesivefilms of the present invention.

This process of manufacture of composite materials accordance with thepresent invention comprises an assembly step of at least one firstelement and a second element by the action of a layer of a resinadhesive or of a foam between the junction surfaces of the two elements,and is characterized by the fact that at least one thermoplasticadhesive film of the present invention is interspersed between theadhesive layer and the junction surface of the first element.

The present invention also is directed to processes for the manufactureof skis, preferably skis used for winter sports, but also summer sportskis, such as water skis, jet skis, wind surfer skis, and surf skis orboards, and most especially for the adhesion of the various elements ofthe ski structure, and of the ski obtained according to this process.

The composite character of a ski structure leads to the ski beingmanufactured by assembly of separate elements that have previously beenimpregnated or coated with thermohardenable adhesives, for example, ofthe epoxy, polyester or polyurethane foam type. This adhesive should becompatible with all elements of the ski that are to be assembled,however, these bonds are not generally efficient to permit all thevarious materials to be glued together that one wishes to use in themanufacture and composition of the ski. Therefore, ill accordance withthe present invention, it is proposed to use thermoplastic adhesivefilms of the present invention in order to obtain adhesion on certainmaterials.

This manufacturing process of a composite structure, such as a ski,comprises of an assembly step of at least a first element and a secondor another element by the action of a resin adhesive layer or a foambetween the Junction surfaces of the elements. This assembly step ischaracterized by the fact that a thermoplastic adhesive film ispositioned between the adhesive layer and the Junction surface of thefirst element.

In the embodiments represented in FIGS. 1-4, there is shown an assemblyof a first element 1 and of a second element 2, at their respectivejunction surfaces 3 and 4, via an adhesive layer 5 positioned betweenthe junction surfaces 3 and 4. As shown, the second element 2 iscompatible with the adhesive 5, that is the adhesive 5 has a goodadhesive power with respect to element 2. However, in the embodimentshown, the first element 1 is made of a material that is not compatiblewith adhesive 5, that is, the adhesive 5 does not have a good adhesivepower at the junction surface 3 of first element 1.

Therefore, in order to effect the assembly of a first element 1 with thesecond element 2, the first element 1 not having good adhesion withadhesive 5, a film 6 composed of a compound according to the presentinvention as described above, that is, a compound of polyamide basedthermoplastic elastomer(s) and of copolymers of modified olefin(s) , ispositioned between the adhesive layer 5 and the junction surface 3 ofthe first element 1. Preferably, the compound of the present inventionis such that the thermoplastic elastomer(s) represent at least about 50%of the total weight of the compound as has been defined.

Insofar as the presence of adhesive 5 is concerned, one embodiment of aprocess in accordance with the present invention for the manufacture ofa composite structure represented in FIGS. 1-4 involves coating thejunction surface 4 of the second element 2 with the adhesive 5, as isrepresented in FIG. 3, before assembling elements 1 and 2 together bypressing the adhesive layer 5 against the film 6 to obtain the assemblyrepresented in FIG. 4.

Another way to ensure or effect the solidarization or unity between thefilm 6 and second element 2 may be accomplished in the case where thesecond element 2 comprises a junction surface 4, formed ofthermohardenable or thermosettable resin that is not entirelycross-linked or reticulated, e.g., a reinforcing element pre-impregnatedwith resin. In this case, as shown in FIG. 2, one can apply the junctionsurface 4 of the second element 2 directly against the film 6 and, byheating, the resin of the second element 2, which is not entirelycross-linked or reticulated, effects the adhesion function, the adhesionbeing obtained by an additional cross-linking of the resin. The resinsgenerally used for this purpose are epoxy, polyester or polyurethaneresins.

One can advantageously use a polyetheresteramide film 6, comprising atleast about 50% by weight and preferably at least about 60% by weight ofpolyetheresteramide, and of a maleic ethylene-propylene copolymer (EPR).This embodiment permits, for example, the adhesion by an epoxy adhesive,or a polyester adhesive or a polyurethane adhesive 5 of a first element1 whose junction surface 3 is composed of at least a material includingthose selected from the group consisting of polyamide, polyethylene,terephthalate polyethylene, polybutadiene terephthalate, polypropylene,processed aluminum, aluminum alloys, aluminum steel, and metal alloys.

In another example, the use of the film 6 of the present inventionpermits the adhesion of a first element 1 composed of a polyamide film11, for example, by an epoxy resin adhesive 5 on a support 2. Theelement 1 may be advantageously used as an upper decorative element,i.e., a cosmetic layer, or protection element of a ski, in which case,for example, the second element or support 2 may be an element ofmechanical reinforcement Including, for example, a woven or non-woventextile reinforcement, made of a material including those selected formthe group consisting of fiberglass, carbon, and aramide, or otherelements. Alternatively, the second element or support 2 can be ametallic reinforcement element made of a material including thoseselected from the group consisting of steel, aluminum, and metal alloys.

In the embodiment represented in FIGS. 1-4, the assembly is accomplishedin successive steps. The first step is illustrated in FIGS. 1 and 2,during which the film 6 is assembled by a technique selected from thegroup consisting of calendaring, heat pressing, and coextruston ofadhesive 5 on junction surface 3 of the first element 1 that is notcompatible for adhesion with adhesive 5. For this embodiment, thetemperature must be elevated to the level of the melting point of thefilm 6. During the second step, the adhesive 5 is applied on thejunction surface 4 of the second element 2, as represented in FIG. 3;during a third step, the layers composed of the adhesive 5 and film 6are applied one against the other, and an assembly, such as representedin FIG. 4, is achieved.

In the embodiment represented in FIGS. 5 and 6, all the elements, films,and adhesive layers are placed in a mold in the following order: a firstelement 1, a film 6, adhesive layer 5, and a second element 2. By heatpressing, all the elements are applied one against the other, and theassembly is achieved in one step. The temperature of the assembly mustagain be raised to the level of the melting point of the film.

Another embodiment of the invention represented in FIG. 7 involvesassembling the elements of the ski structure 1 and 2 by injection of apolyurethane and expandable type of thermohardenable foam 51. The foam51 is not compatible with all the elements to be assembled. The adhesionis ensured by interspersing a film in accordance with the presentinvention, i.e., an adhesive film 6, between the foam 5 and the elements1 and 2 to be glued. A first element 1 of the ski structure, an adhesivefilm 6, and then a second element 2 have previously been placed in amold 8. Then, a polyurethane foam 51 is injected into it which, afterits expansion and hardening phases, adheres perfectly to the adhesivefilm 6 and the first element 1. The heat given off by the exothermalreaction is generally sufficient to bring the adhesive film 6 to itsmelting point and to bring about the adhesion of the elements of thestructure; however, one can introduce additional heat after or duringthe molding operation.

In a similar manner, the adhesive film 6 can be positioned between thefoam 51 and the second element 2, when the second element 2 does nothave adhesive compatibility or only a weak adhesive compatibility withthe foam 51. In this case, the film preferably has the special form of atubular envelope 61 in which the foam 51 is injected, as is shown inFIG. 8. The tubular envelope 61 has the advantage of assuringimpermeability against a possible spill over of the foam 51.

It is understood that the present invention is not limited to theembodiments that lave been explicitly described herein, and its scopeincludes the diverse processes of gluing elements in other applicationsin all other fields such as that of automobile equipment, of anti-noiselaminates, of thermal insulation, of shoe soles, of isothermiccombinations, and the like.

As a further example of the present invention, these adhesive films canbe used in the manufacture of foam products covered with fabricaccording to the known technique of "foam baking". In a first step, afabric/film complex is manufactured in a lamination machine; theresultant fabric/film comprises at least one layer of fabric and one offilm of the present invention and possibly, a layer of foam. Thecompound thus manufactured is positioned in a mold and athermohardenable type of foam, preferably of polyurethane, is injectedinto it. The expansion reaction in situ of the components of the foambrings about the adhesion of the complex.

The following examples illustrate the invention, but are not limiting innature:

Unless indicated otherwise, in all of the examples that follow, theproportions of the components are given by weight.

EXAMPLE I

In a mono-screw extruder, wherein the speed of the screw is adjusted to33 trs/mn, 80 parts of polyetheresteramide (A₁) and 20 parts of maleicethylene and polypropylene copolymers (B¹) are compounded.

The polyetheresteramide (A¹) used is composed of 88% of PA-12 sequences(Mn=1000) and of 12% of sequences of PTMG (Mm=1000).

The extrusion temperature is maintained at a temperature within therange of about 200° C. and 220° C., arid the output of the extruder isfixed to 30 kgs per hours.

When it exits from the dye, the resultant composition is in the shape ofrods with an average granularity equal to about 3 mm at a Melt Index(MI) of 1.31 measured at about 190° C. under a load of 2.16 kgsaccording to the norm ASTM D1238.

The maleic EPR used contains 70% of ethylene. Its total anhydride rateis between about 1.08% and 1.5% and its Melt Index (measured at 230° C.under a load of 10 kg) is equal to 9.

The resultant composition obtained above in this Example I is thenextruded into a film under the following extrusion conditions:

extrusion temperature: 184° C./206° C./215° C.

temperature of the channels: 231° C./236 ° C.

temperature of the dye: 228° C./236° C.

The speed of the screw is 80 trs/mn and the speed of the draw-in is 20m/mn.

At its exit from the dye, the thickness of the film is approximately 50μm.

EXAMPLE II

In the same conditions as Example I, a Composition II composed of 70parts of polyetheresteramide (A₂) and 30 parts of EPRm (B₁) arecompounded.

The polyetheresteramide B2 is composed of 88% of PA-12 sequences(Mn=5000) and 12% of sequences of PTMG (Mn-650).

The Composition II is then extruded into a film under conditions thatare identical to those described in Example I.

EXAMPLE III

Using the same conditions as in Example I, a Composition III composed of90 parts of polyetheresteramide (A₂) and 10 parts of EPRm (B₂) arecompounded.

The EPRm (B₂) used contains 50% of ethylene. Its total anhydride rate isequal to 1.26% and its Melt Index (measured at 230° C. under a load of2.16 kg) is equal to 3.

The shore hardness D (5s) of III, measured according to the ISO norm868, is equal to 60.6.

The tear index in traction, measured according to the norm ASTM D638 isequal to 20.9 MPa.

The module of elasticity in flexion at 20° C., measured according to thenorm ASTM D790, is equal to 357 MPa.

Resistance to tear, measured according to the norm ISO 34, (tearparallel to injection) is equal to 147.4 kN/m.

The Composition III is then extruded into a film under the sameconditions as those described in Example I.

Although the invention is described with reference to particular means,materials and embodiments, form the foregoing description, one skilledin the art can easily ascertain the essential characteristics of thepresent invention; and various changes and modifications may be made tovarious usages and conditions, without departing from the spirit andscope of the invention as described in the claims that follow.

What is claimed is:
 1. A film adapted for adhesion, said film having acomposition comprising:a) at least one polyamide based thermoplasticelastomer selected from the group consisting of polyetheramides andpolyetheresteramides: and b) at least one olefin copolymer selected fromthe group consisting of statistical copolymers and sequenced copolymers,said olefin copolymer comprising at least one member selected from thegroup consisting of:i) an olefin copolymer comprising at least twodifferent olefin monomers grafted with a member selected from the groupconsisting of carboxylic acid, an anhydride of carboxylic acid, and asalt of carboxylic acid, and ii) an olefin copolymer comprising at leastone comonomer selected from the group consisting of vinylic esters ofsaturated carboxylic acid, saturated mono-carboxylic acids, saturateddi-carboxylic acids, esters of saturated mono-carboxylic acids, estersof saturated di-carboxylic acids, salts of saturated mono-carboxylicacids, salts of saturated di-carboxylic acids, anhydrides of saturateddi-carboxylic acids, and anhydrides of unsaturated di-carboxylic acids,wherein said olefin copolymer has an olefin content of at least 50%based on the total weight of said olefin copolymer.
 2. The filmaccording to claim 1, wherein said olefin copolymer has an olefincontent of at least 60% based on the total weight of said olefincopolymer.
 3. The film according to claim 1, wherein the weighted ratioof polyamide based thermoplastic elastomer to polyamide basedthermoplastic elastomer and olefin copolymer is greater than about 0.5.4. The film according to claim 3, wherein said weighted ratio is greaterthan about 0.6.
 5. The film according to claim 1, wherein said olefincopolymer is selected from the group consisting of maleinatedethylene-propylene rubber, and maleinated ethylene-propylene-dieneterpolymers.
 6. The film according to claim 1, wherein said film furthercomprises additives selected from the group consisting of pigments,dyes, and up to about 50% by weight of fillers based on the weight ofsaid polyamide based thermoplastic elastomer and modified copolyolefin.7. The film according to claim 6, wherein said additive comprisesfillers present in an amount up to about 40% by weight based on theweight of said polyamide based thermoplastic elastomer and modifiedcopolyolefin.
 8. The film according to claim 1, wherein said olefincopolymer comprises at least one member selected from the groupconsisting of:a) ethylene-propylene copolymers grafted with a memberselected from the group consisting of carboxylic acid, an anhydride ofcarboxylic acid, and a salt of carboxylic acid, and b) maleinatedethylene-propylene rubber, and maleinated ethylene-propylene-dieneterpolymers.